Characterization of the binding of 125-I-labeled epidermal growth factor to human fibroblasts.

摘要: Epidermal growth factor (EGF) was labeled with 125-I by a lactoperoxidase technique. The unlabeled, monoiodinated and diiodinated species were separated DEAE-cellulose chromatography found to possess equivalent biological activities. binding of epidermal human fibroblasts specific in that unrelated polypeptides did not affect the reaction. reaction saturable process time- temperature-dependent. A Scatchard analysis data indicated each cell capable approximately 100, 000 molecules 125-I-EGF. apparent dissociation constant for calculated be 2.7 4.3 times 10-minus 10 M. Subsequent 125-I-EGF fibroblasts, degraded cell-mediated proteolysis [125-I]monoiodotyrosine appeared medium. extent degradation reduced protease inhibitors, tosyl-L-lysine chloromethyl ketone benzyl ester guanidobenzoic acid. Active sites 125-I-egf present some but all types. These results demonstrated cells derived from number (human, mouse, rat, chick) possessed receptors interacted this mouse-derived factor.